package de.metas.util.collections;

import java.util.Iterator;

/*
 * #%L
 * de.metas.util
 * %%
 * Copyright (C) 2015 metas GmbH
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 2 of the
 * License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public
 * License along with this program. If not, see
 * <http://www.gnu.org/licenses/gpl-2.0.html>.
 * #L%
 */

import java.util.NoSuchElementException;
import java.util.stream.Stream;

/**
 * A Blind Iterator is an iterator which does not have the look-ahead method (i.e. hasNext()).
 * 
 * It only has the {@link #next()} which returns the next element or NULL if there are no more elements.
 * 
 * @author tsa
 * 
 * @param <E>
 */
@FunctionalInterface
public interface BlindIterator<E>
{
	/**
	 * Returns the next element in the iteration or <code>null</code> if there are no more elements.
	 * 
	 * @return the next element in the iteration or null
	 * @throws NoSuchElementException implementations could throw this exception if repeatedly called after end was reached
	 */
	E next();

	default Stream<E> stream()
	{
		return IteratorUtils.stream(this);
	}

	default Iterator<E> iterator()
	{
		return IteratorUtils.asIterator(this);
	}
}
